Food Allergy? Intolerance? What’s the difference?
Food allergies and intolerances present themselves in such indistinct and variable ways, and are generally slightly different for each person. Symptoms may range from mild to severe in a given individual, depending on whether and if so which part of the immune system is activated and how long it takes for the reaction to occur. Treating such conditions is possible, but it’s important to know the difference between an actual food allergy and an intolerance.
Two of the more common processes associated with Food Allergies are Type I and Type IV Hypersensitivity reactions.
Type I Hypersensitivity occurs where reactions occur within minutes and are usually much more serious. In this case, an individual will typically not have a reaction the first time they are exposed, however after that sensitization occurs, subsequent exposures can result in severe reactions including anaphylaxis and even death. Two examples of Type I Hypersensitivity include peanut and bee venom allergies.
Type IV Hypersensitivity is generally a more delayed reaction, where symptoms can present themselves over the next 30 minutes to 72 hours. Symptoms of Type IV Hypersensitivity vary considerably, ranging from bloating, gas and abdominal cramps to headaches and fatigue to eczema, acne rosacea and dandruff, etc. Individuals with this form of allergy can experience reactions upon first exposure. The rash one experiences from poison ivy would be an example of a Type IV Hypersensitivity.
An intolerance to any food does not involve activation of the immune system, rather it is related to the body’s inability to process or digest a component of that food, commonly due to lack of the proper enzymes. A well known example is insufficient Lactase, the enzyme that is required to digest the milk sugar lactose. The symptoms of food intolerances may be similar to Type IV Hypersensitivity reactions, for example abdominal pain/cramping bloating and gas.
It is important to understand the difference between food allergy and food intolerance:
A food allergy is an abnormal reaction to proteins in a food, is usually triggered by the immune system, and can cause serious illness or even death. The reactions occur within about 5 minutes, and do not depend on the amount of the food eaten. A dab of peanut oil can cause the same reaction as a smear of peanut butter.
Alternately, food intolerance is generally due to insufficient levels of the enzyme required to digest the food. It is delayed, usually occurring ½ - 72 hours after exposure and its severity depends on how much of the food you’ve eaten. The main know intolerances are due to histamine (high in cheese, wine and fish), fructose (fruit sugar), lactose (milk sugar) and gluten (a component of certain cereal grains like wheat, rye and barley).
To further complicate matters…
Not only are there allergies and sensitivities, some other reactions that cause allergy-like symptoms but don’t involve immune responses include:
Toxic reactions to bacterial toxins (such as in food poisoning)
Symptoms that are really caused by food additives (dyes, MSG, etc) or medications
Psychological triggers that may cause certain people to react to foods, circumstances, environments, etc
Even more problematic in diagnosing, one person can have a spectrum of reactions depending if they have more than one problem occurring (for example intolerance + allergy) as well as which particular foods they may be allergic and/or intolerant to. If you think you might have food allergy of intolerance, speak to your Naturopathic Physician who will know which investigations and tests need to be performed so that you are able to pinpoint where the problem may be. In some cases, people may outgrow certain sensitivities, especially if they’ve presented themselves in childhood, but if not, your Naturopath can help you learn to manage, prevent and possibly treat your symptoms so that you can enjoy you food and be more comfortably and healthily now and in the future!
Dr Katarine Holewa, ND